Photographic developing agents



Patented July 15, 1952 UNIT ED STATES PATENT OFF-l CE;

2,603,656 PHOTOGRAPHIC DEVELOPING AGENTS. Elmore Louis Martin, Wilmington, Del., assignor to E. 1.. du Pont de Nemours and Company, Wilmington, DeL, a corporation of Delaware No Drawing. Application February 27', 1951, Serial No. 213,051

This invention pertains to a new class of, N- substituted aminoaniline derivatives. More par.- ticularly it pertains to N=alkyl-N-.(sulfphenyloxy)all ylanilines. These compounds are useful 'as photographic developing agents.

Various aryle'nediamines have been used as photographic developing agents, but the most .importantof them, namely, para-phenylenediamine and its lower- N,N-dialky1 derivatives.- have the disadvantage that. they are readily absorbed .by-the skin and give rise to dermatitis. Since these. agents are strong photographic developers and, readily couplewith, color formers during the development of latent silver halide images to produce quinoneimine or azomethine dye images insitu.withthe silver images-they are used in mostcommercial. processes of color photography. The, compounds, however, due. to their toxicity constitute a health hazard in. photographic. de-

{veloping laboratories.

An object. of. this invention is to provide a new class of. photographic developing agents.

.A. further object is to provide a. new class of photographic developing agents. which are useful in chromogenic development and are free from, toxic effects. The more specifieobject is to provide a new class of N-alkyl-N(sulfophenyloxy) alkylanilines. Still other objects will be apparent from the-following: description of the invention.

The new compounds ofthi's invention may be represented by the following general formula:

alkoxy" group; n is a positive integer from 2 to '10- and alkyl contains irom 1 to 6 carbon atoms. Among the useful alkyl radicals for R there may I be mentioned -CH3, C2H5, CH(CH3)2 and among the'useful substituted alkyl radicals R there may be mentioned-CHzQl-I and -CH2C1.

Suitable; specific alkoxy radicals for Ruinclude and --0C2Hs -OCI-I(CH3;)2. R, however, preferably is hydrogen or an unsubstituted alkyl or alkoxyxradicaloi, 1.to 3 carbonatoms.

It is important: that the tertiary mtrogen, atom and the .suliopheny-l group in theabove. compounds be separated by at least two. methylene (CH2) groups in order to obtain a high degree 4 Claims. (Cl. 260-509) loid silver halide emulsion layer andit is more difficult to Wash such compounds out oi the colloid silver halide emulsion layers.

The compounds of Formula I may beprepared by the following series of chemical reactions: (a) preparation of an N.-alky1-N.-(phenoxyalkyl) aniline by reaction of an omega-halogen substituted alkyl. phenylether containing the halogen and ether groups on the opposite. ends 9 the straight chain. alkylene radical with N- alkylanilina'e. g;., N-methylaniline, N.-ethyla-- line or N-butylaniline. This reaction is us carried out under neutral to alkaline 091. tions; (22) preparation of; N-alliy -N-iem sa-s fophenyloxyalkyl):anilines by the reaction oi the tertiary aminederivative obtained in stepq with a sulionating agent. e, g... hot. concentrated suliuric acid; (.6). preparation (lithe. orresponding P- r -N-a kyln-N- (omega.- su ioehenrlexralmula I.

when N methyl, ethylnmstoluidine, N-methyl, ethyl-m-anisldine, or similarly nuclear substifluted N-alkyl amines are. used in p a e. of; N- alkyl aniline in the above syntheses one bta n the. corresp din ly substitu ed. derelopers,

s invention will be further. illu t tediby thefollowing examples. They exe liiy sui able sp i me ods for he p epar n hecoinpounds and illustrate heir uses n pr pert e but, are, not intended to limit the invention.

E AMP E. 1'

P-AMINO-N-ETH'YL-N EOMEGAW- g-Swmo mmqgyy PiioPYMANmINE- A. N-ethyl-N- ('omegawhenowypropyl) aniline ome a-bro osro vl phenyl ethe 2115513 0.5 mol) and N-ethyla-nil-ine (242 gra ns, 1- were heated one steam a for 15: ou s, u' lh product was washed with-a solutionoi 22 grams of sodium hydroxide in 300 milliliters of iollowed by a water wash, and dried, Dis llation gave 209 grams (92%) at 186-8" 331,; n =1.5753.

B. N -ethyZ-N [omega- (p-sulfophenoxy) prom/Z] aniline N-ethyl-N- (omega-phenoxypropyl) aniline (51 grams) was added in a thin stream to 45 ml. of

sulfuric, acid in a stirred flask. The mixture was kept at;90 C. for 0.5 hour, then cooled and poured onto 75 grams of ice. The aqueous layer was removed from the syrup which separated and replaced with '75 milliliters of water. The product crystallized on standing. It .Was recrystallized from water; yield 32 grams, M. P. 222-4 C.

C. p Nitroso N ethyl N [omega (17- sulfophenoxy) -propyll aniline D. p -Amino-N ethyl N-[omega-(p-sulfophenoay) propyll aniline Ninety-one-grams of the above nitroso compound was dissolved in grams of NaOH plus 130 milliliters of water,charged into a shaker tube with 2 grams of palladium-on-charcoal catalyst and hydrogenated at 25-55 C. and 200- 1000 lbs/sq. in. for one-hour.

The product was treated with a little sodium hydrosulfite and a decolorizing charcoal and --filtered. The pH of the solution. was adjusted "to 6 which caused the product to separate as asyrupr The water was separated and the syrup was rubbed'with dioxane to cause Yield, 86 grams (82%).

iir-Amho-N-Errrrrl N [4 (P-StJLFoPHErIoxfl "ANILINE l I v 'A,4-phen 0:l:11/batg/Z bromide. i 2.11m, smegma flasli' 'equipped witha Ustirr'er, condenser and dropping funnel were;

"placed 158 "grams of 88% phenol, 402' grams of tetramethylenedibroinide and 750 'milliliters of (water; .Thei mixture was refluxed and during 0.5 hour 57 grams of sodium hydroxide in 190 milliliters of waterwas 'added- The mixture was refluxed five hours longer, after, which it was'cooled, the organic layer was separated, dried and distilled. A 50% yield (169 grams) of 4-,phenoxybutyl bromide boiling at 166-170 C./20 mm. was obtained.-

B. N -ethyZ-N- (4-phenoscybutyl) aniline phenoxybutyl bromide (168 grams) and N- 'ethyl aniline (178 grams) were heated three 1 1 hours at 125 C. The product was cooled and shaken with 32 grams of sodium hydroxide in 500 cc. of water. The amine was separated,

dried and distilled and 81% yield (159 grams) boiling at 226-9 C.

/2 mm. was obtained; n =1.5709.

it to crystallize,

-- D. p-Nitroso-N- C. N-ethyl-N- [4- (saljophe-nomy) butyl] aniline N ethyl N (4 phenoxybutyhaniline (159 grams) was run in a thin stream into 127 milliliters of sulfuric acid with cooling so that the temperature did not rise above 90 Cf. v The solution was heated on a' steam bath at 90-96 C. for 0.5 hour. The mixture was poured onto 200 grams of ice and the solution of the sulfonated products, which was completely soluble in sodium hydroxide solution, was used directly for nitrosation.

ethyZ-N- [4- (p-snljophenory) butyl] aniline The above solution was mixed with 75 milliliters'of hydrochloric acid and stirred at 0-5" C. while 43 grams of sodium nitrite in 60 milliliters of water was added dropwise. Crystallization was started by scratching the product. After the mixture had stirredforjone hour, the nitroso "compound was filtered off and washed with water. "The yield was 174 grams or 78%. The compound 'may be crystallized in small portions from water.

ethyZ-N- 4 (p-salfophe mi ne 1 Eighty-five grams of the above nitroso 'c ompound was dissolved in 120 milliliters oflwater containing 9 grams of sodium hydroxide and E. p-Amino-N- norwcharged-into a shaker tube'with 2 gramsof-palladium-on-charcoal catalyst. Hydrogenation for one hour. The product "Wasmixed with50 milliliters of hydrochloric acid and the'catalyst wasfiltered off with theaid of a silicous flltering aid. A small amountof sodium hydrosulilte was added to the filtrate and sodium hydroxide 'solution was added to a pH of about 6. 7 Ayield of 62.5 grams of the amino acid separated. The amino acid was recrystallized from water. The

; compound had water of crystallization which was pears that the c0 "1.00. Found: 6.94, 6.84.

gradually lost on heating in an oven,' but-1t apmpound separates with two molecules of water. I 1

Analysis calculated for A stirred mixture of 300 grams of hexamethyl- 'ene dibromide, 105 grams of 88% phenol and 500 milliliters of water was refluxed while 37.5 grams of sodium hydroxide in 125 milliliters of water was added during 0.5 hour. After five hours of reflux, the mixture was cooledand the organic layer was separated, dried and distilled. The yield of 6-phenoxyhexyl bromide, boiling at m-awas 63- r ms or. 2

B. Ma t -N-aaiamhmmmzaq, phenoxyhexyl1bromide I 51.5 grams, 0.2 mol) i and N-ethyl aniline" (48.5 grams,"0.4"mol) ==were heated for 15 hours on a steam bath. 'I'l1e;prodnot was shaken with 10 grams 01 sodium hydroxide in millilitersof Water and the amine layer was separated, "dried and distilled. 1 The -=yield of N-ethyl-N-.(fi-phenoxyhexyllaniline was i 43.5 grams '6; N -ethyl-N- i6- (p-sulfophenomy'lhexyll aniline N-ethyl-Nr fi-phenoxyhexyllaniline (4]. grams) was added to 33 milliliters of sulfuricaacidwith stirring. The-temperaturexwas. kept at 9010. during the addition and the mixture was then heated: at 90-95 C. for'0.5 hour. The sulfonated product was cooled and poured onto 100 grams 6 types-of compound's of thisinvention as compared witl r those of' p-amino-NN-di'ethy-l aniline are set forth inthe fbllowingtable:

Taib-le v zHr't.

MONOLAYER COATINGS V 7 Block Speed Gamma Base-l-Fog CD-I 1r= 2" n=3 n=4 n=6 OD-l n=2 n=3 n=-t ;n=6 OD-l n=2 n==3 n=4 n=6 Oyan..- 5.0- s. 1 4: s: 4.7-; 5.0 3': 70' "2.55 4.23 4:24 K4505 0.13" 11* o-. 13 :13 "0;1'4 Magenta 6. 7 4. 2 6:2 5. 7, 7. O 2314.; 2 1. 25 2.51.' L 73" (1171. 0". 20, 0.15" 20. 19 O. 12 1' 0.16 Yellow; 6. 0 3. 0 4'. 6 4'. 7 5. 4 1.93 0. 1 42 1 1 3 2 1. 5& 0.119,. 0. 0. 06- 0..08 0. (19

MUIJTILAY E R 00mm.

Cyan 5. 2 3. 7 4. 8 4. 7 5. 3 3. 36 2. 57 3. 72 3. S3 3. 29 0. 12 D. 11 0. 15 0. 10 O. 32 Magenta 4. 5 1. 6 3. 3 3. 5 4. 3 2. 48 0. 62 2. 27 2. 69 2. 34 0. 11 O. 09 0. 12 0. 12 O. 28 Yellow 4. 6 1. 8 3. 5 3. 9 3. 6 1. 44 0. 32 1. 64 1. 34: 1. O0 0. 14 0. O9 0. 09 O. 14 0. 26

CD-1 p-Amino-NiN-diethyl aniline. of ice. This solution was used directly for nitrosation after 50 milliliters of water and 120 milliliters of hydrochloric acid were added.

D. p-Nitroso-N-ethyZ-N- [6- (p-sulfophenoxy) hexyl] aniline To the above solution was added with stirring 10 grams of sodium nitrite in 15 milliliters of water at 0-5 C. The mixture was stirred for one hour, 400 milliliters of water was added, and the inside of the flask was scratched to induce crystallization. After two additional hours of stirring, the nitroso compound was filtered off and washed with water. The yield was 39 grams or '7 0%. The compound was recrystallized from water.

E. p-Amino -N-ethyZ-N- [6- (sulfophenoxy) hexyl] aniline Thirty grams of the above nitroso compound was dissolved in a solution of 3 grams of sodium hydroxide in 100 milliliters of water and charged into a shaker tube with 2 grams of palladium-oncharcoal catalyst and hydrogenated at 50-60 C. and 1500 lbs/sq. in. for 1.5 hours. The product was filtered and one equivalent of hydrochloric acid was added to precipitate the amino acid as a syrup. The syrup was rubbed with dioxane to cause it to crystallize. The yield was 21 grams. The product was recrystallized from water.

Analysis calculated for C2oH2aN2O4S.2H2O2 N, 6.56. Found: N, 6.64, 6.69.

EXAMPLE IV P-AMmo-N-ErHYL-N [BETA- (P-SULFOPHENOXVY) ETHYL] ANILINE When the general procedure of Example I was repeated except that beta-bromoethyl phenyl ether was employed in place of the omega-bromopropyl phenyl ether there was obtained upon condensation with aniline, N-ethyl-N-(beta-phenoxyethyl) aniline, B. P. 154-156/3 mm.; n =1.5860.

Treatment with sulfuric acid gave N-ethyl- Nibeta- (p-sulfophenoxy) ethyl] aniline. Treatment of the latter under acid conditions with sodium nitrite gave p-nitroso-N-ethyl-N-[beta- (p-sulfophenoxy)ethyllaniline, which upon reduction gave the corresponding amino compound. The hydrochloride had the following analysis:

Calculated for C1oH21N204SI N, 7.53; S, 8.60. Found: N, 7.58; S, 9.09.

The photographic developing properties of the In the foregoing table the cyan, magenta and yellow coatings were dispersions of light-sensitive silver iodobromides in polyvinyl acetal color formers of aromatic halides of the type described in U. S. Patents 2,397,864 and 2,380,033 and U. S. applications Ser. Nos. 9,330, filed February 18, 1948, now U. S. Patent No. 2,513,190, issued June 27, 1950, and 29,921, filed May 28, 1948, and now U. S. Patent No. 2,538,257, issued January 16, 1951. In the table gamma refers to the development factor and fog relates to the density of development in the'unexposed portion of the photographic film. Block speed is an arbitrary figure indicating the speed of the developer. If a developer has a block speed one unit less than another, this means that the photographic film will require about twice the degree of exposure to give an image of the same density as the second under the same conditions of development. Gamma is defined in Neblette, Photography, page 412 (published by D. Van Nostrand Com- ;pany, 1942). Values of block speed and/or gamma comparable or superior to those of the commercial developer, p-amino-N,N-diethyl aniline, are important. Increases are shown in the table for certain of these values. Particularly important is the fact that the new developers cause less fog than the p-amino-N,N-diethyl aniline.

The compounds of this invention when used as photographic developing agents may be employed alone or in admixture of alkali salts such as sodium carbonate. sodium sulfite or other conventional agents of photographic developers. They may be used as the free acid or as a suitable derivative of the sulfonic acid group, e. g., the alkali metal or ammonium salt, according to the solubility requirements of the system. The developing agents may be used in developer formulations containing color formers for color development of exposed silver halide contained in gelatin or synthetic water-permeable colloid binding agents for silver halide grains. They may be used in the color development of photographic films containing immobile color formers in the light-sensitive silver halide emulsion layers, particularly films of the type described in U. S. Patent No. 2,397,864.

The compounds of Formula I, however, are not limited in their use as photographic developing agents. To the contrary, they are useful chemical intermediates and may serve as a basis for the preparation of various other chemical com- 7 v esn m ny widely diffe ent em o imentsie i v n io can h -ma e -wiih u eb ng mm the spirit and scope-thereof, it is tcbe nderstood that the invention is not to be limited except as defined by the claims.

What is claimed is:

Twhere Ft isc a. member taken frona the groub consisting of hydrogen, alkyl radicals of 1 to3 carbon atoms and alkoxy radicals of 1 m3 carbon atoms,

noxy) propyllaniline. I v v 3. p Arnino-N-ethyl-N- [-(p-sulfophenoxy) buty1]am1ine.' I 5 i 4; p --Ax'nino-N-e'thy1j-N-[6 (pesuifophenoxyihexyl] aniline v ELMORE LOUIS MAR'IIIEVN. REFERENCES CITED The following references are of record in the r 9? t i e n i UNITED STATES PATENTS Number 1 2,163,166 2,241,769

alkyl contains 1 to 6 carbon atoms and n is e 7 cardinal number from 2 to 6 inclusive. 1

Name Date WiIm'anns et a1. June 20, 1939 Dickey et a1 May 13, 1941 

1. THE CHEMICAL COMPOUNDS OF THE GENERAL FORMULA: 